Magnetic holding drum

ABSTRACT

A magnetic holding drum particularly suitable for optical reproduction devices such as facsimile transmitters, which enables the copy to be held substantially flat over the surface of the drum while the drum is either rotated or optically scanned. The drum includes a plurality of spaced-apart, radially disposed elongated magnets on its cylindrical surface. A sliding holder which is slidably retained in grooves at each end of the drum is magnetically affixed at any desired position on the surface of the drum in order to maintain the copy flattened against the drum&#39;&#39;s surface.

United States Patent Inventor Edmund F. Priessnetz Baldwin, N.Y. ApplNo. 872,238 Filed Oct. 29, 1969 Patented May 25, 1971 AssigneeElectronic Transmission Systems, Inc.,

New York, N.Y.

MAGNETIC HOLDING DRUM 7 Claims, 4 Drawing Figs.

11.8. CI 335/285, 1 01/3 82 Int. Cl Hillf 7/20 Field of Search 335/285,

306; 248/206 (A); 101/382 (MV) [56] References Cited UNITED STATESPATENTS 3,039,389 6/1962 Meese et al l0l/382(MV) 3,353,481 11/1967Antonucci lOl/382(MV) Primary ExaminerG. Harris Attorney-Allison C.Collard ABSTRACT: A magnetic holding drum particularly suitable foroptical reproduction devices such as facsimile transmit ters, whichenables the copy to be held substantially flat over the surface of thedrum while the drum is either rotated or optically scanned. The drumincludes a plurality of spaced-apart, radially disposed elongatedmagnets on its cylindrical surface. A sliding holder which is slidablyretained in grooves at each end of the drum ismagnetically affixed atany desired position on the surface of the drum in order to maintain thecopy flattened against the drums surface. 7

PATENTED M25 1971 INVENTOR. EDMUND F. PRIESSNETZ m.- Q m ATTORNEYMAGNETIC HOLDING DRUM This invention relates to a magnetic holding drumfor use with optical reproducing apparatus for maintaining a copysubstantially flat on the surface of the drum.

More specifically, this invention relates to a magnetic holding drumhaving a plurality of radially spaced-apart elongated magnets disposedon the drums surface for magnetically securing the copy materialsubstantially flat on the surface of the drum.

ln reproducing apparatus and particularly those utilized for facsimiletransmission, a drum is commonly provided for holding and maintainingthe copy material for optical scanning. ln facsimile transmitters, wherethe drum which holds the copy material is rotated at high speed while itis viewed by an optical scanning device, it is important that the copymaterial be maintained substantially flat against the surface of thedrum in order to prevent distortion of the reproduced copy. Conventionaldrums are generally provided with mechanical fastening devices which aredesigned to engage the copy at each end and retain it on the drumsurface. For drums which rotate at high speeds in front of opticalscanning devices, these conventional mechanical fasteners often becomeeither partially or totally disengaged from the copy material so as tocause its information surface to depart from the surface of the drum,thereby causing distortion of the subsequently reproduced copy on thefacsimile receiver. Attempts to overcome these difficulties so as tomaintain the copy material more rigidly on the surface of the drum haveresulted in complicating the mechanical holding fasteners, and making itmore difficult to quickly change the copy material on the drums surface.

Accordingly, the present invention provides an improved holding drumwhich utilizes magnetic means coupled to the fastening devices in orderto secure the copy material substantially flat on the drums surface. Thesurface of the drum according to the invention is provided with axiallyspaced-apart magnetic strips which are embedded into the cylindricalsurface of the drum. On one segment of the drums surface is disposed ahinged or pivoted clamp for gripping the leading edge of the copymaterial. The clamp is magnetically held in its closed position againstthe paper copy by the surface magnets. The end flanges of the drum areprovided with a track which engages a sliding element constructed from aflat paramagnetic material which is utilized to flatten the copy againstthe drums surface. As the sliding element is advanced toward thetrailing edge of the copy material, it will be magnetically retained inplace and drawn against the copy surface. The magnetic force applied tothe paramagnetic sliding element is sufficient to prevent the slidingelement or copy material from changing position during the high speedrotation of the drum. Furthermore, no additional fastening devices arerequired to lock the slider in place or secure the copy to the drumssurface. Moreover, when the sliding element is moved over the surface ofthe copy material toward its trailing edge, it serves to flatten andpress the copy material against the drums surface so as to remove anyuneven portions thereof.

After the copy material has been reproduced, it can be easily andquickly removed from the surface of the magnetic drum by merely movingthe sliding element away from the copy surface and opening the hinged orpivotably mounted clamp away from the leading edge. This will interruptthe magnetic engagement on the paper clamp.

It is therefore an object according to the present invention to providea magnetic holding device capable of retaining copy materialsubstantially flat against the surface of the drum.

It is another object according to the present invention to provide amagnetic holding drum which includes a plurality of magnetic stripsembedded in its surface for retaining the copy material.

It is still a further object according to the present invention toprovide a magnetic holding device which is simple in design, easy toconstruct, and reliable in operation.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in connection withthe accompanying drawing which discloses one embodiment of theinvention. It is to be understood, however, that the drawing is designedfor the purpose of illustration only and not as a definition of theinvention.

In the drawing, wherein similar reference characters denote similarelements throughout the several views:

FIG. 1 is a perspective view of the magnetic holding device according tothe invention;

FIG. 2 is a cross-sectional view taken along section 2-2 of FIG. 1;

FIG. 3 is a further cross-sectional view taken along section 3-3 of FIG.1; and

FIG. 4 is a still further cross-sectional view taken along section 4-4of FIG. 1.

Referring to FIGS. 14 there is shown the magnetic holding drum 1including end flanges 12 and 17, pivotably mounted on shaft 11. Acrossthe cylindrical surface of drum 10 is disposed a gripper or clamp 13which includes hinge pieces 23 secured to each end. Hinge pieces 23include a shaft 24 which projects through corresponding bores in endflanges 12 and 17. Clamp 13 includes a pair of handles 18 secured ateach end to permit the easy raising and lowering of the catch over theleading edge of copy material 14. Disposed around the cylindricalsurface 21 of drum 10 are a plurality of permanent magnets 22constructed from thin strips of magnetic material which are secured inspaced-apart positions on the drum surface extending generally parallelto the axis of shaft 11. Magnetic strips 22 may also be spirally woundaround drum surface 21 or assume any other configuration.

Disposed on drum 21 is also a sliding element 15, having its endportions slidably inserted into circular tracts 20 which are containedon the internal sides near the rims of end flanges 12 and 17. Slidingelement 15 also includes a handle or finger grip 16 secured to its topsurface, so that it may be easily moved over drum surface 21 and copymaterial 14 to flatten the copy material against the drum surface. Assliding element 15 approaches the end of copy material 14, as shown indetail in FIG. 4, it can be retained in place by the attraction of onemagnetic strips 22 closest to the end of the copy material. No furthersecurement of sliding element 15 will be required. Clamp or gripper 13is also retained in its closed position by another one of magneticstrips 22 so that it will not release the leading edge of the paperduring the movement of the drum surface. Both sliding element 15 andclamp 13 are constructed from a paramagnetic material such as steel,nickel, etc., so as to cooperate with magnets 22. Drum surface 21 ispreferably constructed from a nonmagnetic material, such as aluminum, soas not to interfere with the magnetic attracting forces of strips 22.End flanges '12 and 17 are secured to the end of drum 10 by means offastening screws 19 and are also preferably constructed from a metal orrigid material sufficient to support drum surface 12 on shaft 11. Copymaterial 14 will generally consist of paper or a flexible sheet materialcontaining information. Magnetic strips 22 may be permanent magnets, orelectromagnets.

While only a single embodiment of the invention has been shown anddescribed, it will be understood that many modifi cations and changesmay be made thereunto without departing from the spirit and scope of theinvention.

What I claim is:

1. A device for holding a copy material comprising:

a drum having a substantially cylindrical surface,

clamp means for retaining one edge of said copy material,

sliding means for retaining the other edge of said copy material, and,

magnetic means secured to said drum surface for magnetically engagingsaid clamp means to said drum surface.

2. The device as recited in claim 1, wherein said magnetic meanscomprises at least one magnetic strip disposed within the surface ofsaid drum and substantially parallel to its axis.

means and said sliding element are constructed from paramagneticmaterial, and said magnetic strip is disposed for magnetic engagementwith said sliding means.

6. The device as recited in claim 1, wherein said magnetic meanscomprises a plurality of permanent magnet strips embedded in said drumsurface.

7. The device as recited in claim 6, wherein said drum surface isconstructed from a nonmagnetic material.

1. A device for holding a copy material comprising: a drum having asubstantially cylindrical surface, clamp means for retaining one edge ofsaid copy material, sliding means for retaining the other edge of saidcopy material, and, magnetic means secured to said drum surface formagnetically engaging said clamp means to said drum surface.
 2. Thedevice as recited in claim 1, wherein said magnetic means comprises atleast one magnetic strip disposed within the surface of said drum andsubstantially parallel to its axis.
 3. The device as recited in claim 2,wherein said drum additionally comprises a pair of end flanges securedto the ends of said drum, an annular groove formed in each of saidflanges and directed toward said drum surface, said grooves slidablyretaining said sliding means.
 4. The device as recited in claim 3,wherein said clamp means additionally comprises pivot means secured toeach end and pivotably coupled to each of said flanges.
 5. The device asrecited in claim 4, wherein said clamp means and said sliding elementare constructed from paramagnetic material, and said magnetic strip isdisposed for magnetic engagement with said sliding means.
 6. The deviceas recited in claim 1, wherein said magnetic means comprises a pluralityof permanent magnet strips embedded in said drum surface.
 7. The deviceas recited in claim 6, wherein said drum surface is constructed from anonmagnetic material.